In the past, there has been provided an electric hair clipper configured to cut human head hairs by use of a comb-like fixed blade and a comb-like movable blade reciprocated relative to the fixed blade. For example, such an electric hair clipper is configured to vary a clipping height by means of attaching a specific attachment for adjusting the clipping height.
The aforementioned attachment has a comb-like member covering a blade part of the hair clipper, and forms a space between the blade part and a human skin. The clipping height can be varied with a change in an attaching position of the attachment.
In these kinds of hair clippers, a latching mechanism may be adopted for changing the attaching position of the attachment. With regard to a hair clipper with such a latching mechanism, when the attachment is pressed against one's skin, a position of the attachment may be changed. Such a change in the position of the attachment causes a change in the clipping height.
JP 1-214388 A discloses a hair clipper including a main body incorporating a motor therein and a handle ring attached to the main body in such a manner to be allowed to rotate about an axis and to slide in an axial direction. As for this hair clipper, a pin-shaped protrusion protruded from an outer periphery of the main body is engaged with a spiral cam groove formed in an inner periphery of the handle ring, and an attachment with a comb member is linked to an apical end of the handle ring. When the handle ring is rotated, engagement between the spiral cam groove and the protrusion causes the handle ring to move along the axial direction. As a result, the position of the attachment is varied.
In this situation, since a rotational motion is converted into a motion in the axial direction by means of the spiral cam groove and the protrusion, pressing the attachment does not cause a great undesirable backward movement of the attachment. Thus, the clipping height is not greatly changed.
However, the spiral cam groove has an inner surface along its lengthwise direction, and the inner surface is an inclined surface oblique to the axial direction (sliding direction) of the handle ring. Hence, the attachment may be displaced due to a load caused by pressing the attachment against one's skin surface, or due to vibration of the motor. Further, the attachment may be inclined when a pressing direction of the attachment against one's skin is not approximately parallel to a lengthwise direction of the main body. Such displacement or inclination of the attachment may deteriorate an accuracy of the clipping height.